84 research outputs found

    The role of deactivation of cyclohexane oxidation catalyst in caprolactam production

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    Screening of new catalytic systems over the model equipment for oxidation of cyclohexane shows the absence of resins and precipitates (adipates) on the reactor walls. This confirms that the use of more active and selective catalyst can significantly suppress the formation of resins, and thus prolong the service period and increase the efficiency of industrial reactors

    Elicited bid functions in (a)symmetric first-price auctions

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    We report on a series of experiments that examine bidding behavior in first-price sealed bid auctions with symmetric and asymmetric bidders. To study the extent of strategic behavior, we use an experimental design that elicits bidders' complete bid functions in each round (auction) of the experiment. In the aggregate, behavior is consistent with the basic equilibrium predictions for risk neutral or homogenous risk averse bidders (extent of bid shading, average seller's revenues and deviations from equilibrium). However, when we look at the extent of best reply behavior and the shape of bid functions, we find that individual behavior is not in line with the received equilibrium models, although it exhibits strategic sophistication.This research benefited from financial support from the European Commission through a TMR-ENDEAR Network Grant (FMRX-CT98-0238) and a Marie Curie Fellowship (Sadrieh: HPMF-CT-199-00312) and from the Deutsche Forschungsgemeinschaft through SFB 303

    Periodontal disease affects oral cancer progression in a surrogate animal model for tobacco exposure

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    For decades, the link between poor oral hygiene and the increased prevalence of oral cancer has been suggested. Most recently, emerging evidence has suggested that chronic inflammatory diseases from the oral cavity (e.g., periodontal disease), to some extent, play a role in the development of oral squamous cell carcinoma (OSCC). The present study aimed to explore the direct impact of biofilm-induced periodontitis in the carcinogenesis process using a tobacco surrogate animal model for oral cancer. A total of 42 Wistar rats were distributed into four experimental groups: Control group, periodontitis (Perio) group, 4-nitroquinoline 1-oxide (4-NQO) group and 4NQO/Perio group. Periodontitis was stimulated by placing a ligature subgingivally, while oral carcinogenesis was induced by systemic administration of 4NQO in the drinking water for 20 weeks. It was observed that the Perio, 4NQO and 4NQO/Perio groups presented with significantly higher alveolar bone loss compared with that in the control group. Furthermore, all groups receiving 4NQO developed lesions on the dorsal surface of the tongue; however, the 4NQO/Perio group presented larger lesions compared with the 4NQO group. There was also a modest overall increase in the number of epithelial dysplasia and OSCC lesions in the 4NQO/Perio group. Notably, abnormal focal activation of cellular differentiation (cytokeratin 10-positive cells) that extended near the basal cell layer of the mucosa was observed in rats receiving 4NQO alone, but was absent in rats receiving 4NQO and presenting with periodontal disease. Altogether, the presence of periodontitis combined with 4NQO administration augmented tumor size in the current rat model and tampered with the protective mechanisms of the cellular differentiation of epithelial cells

    The Critical Turning Points Database : Concept, Methodology and Dataset of an International Transformative Social Innovation Comparison (TRANSIT Working Paper # 10, July 12th 2017)

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    [Abstract] This working paper presents the TRANSIT open-access online database on Critical Turning Points (CTP) in Transformative Social Innovation. It specifies the contents of the database, comprising qualitative accounts of more than 450 ‘critical’ episodes in the evolution of social innovation initiatives in 27 different countries. Providing the theoretical-methodological context to these data, the paper also describes the theoretical background of the CTP concept and the methodology though which the CTP accounts have been reconstructed through interviews with members of SI initiatives. The paper concludes with reflections on the open access CTP database as a knowledge infrastructure, discussing its significance in terms of mapping, dissemination and framing of social innovation.This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no 61316

    Comparison of health conditions treated with traditional and biomedical health care in a Quechua community in rural Bolivia

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    <p>Abstract</p> <p>Background</p> <p>The objective of the present study was to reveal patterns in the treatment of health conditions in a Quechua-speaking community in the Bolivian Andes based on plant use data from traditional healers and patient data from a primary health care (PHC) service, and to demonstrate similarities and differences between the type of illnesses treated with traditional and biomedical health care, respectively.</p> <p>Methods</p> <p>A secondary analysis of plant use data from semi-structured interviews with eight healers was conducted and diagnostic data was collected from 324 patients in the community PHC service. Health conditions were ranked according to: (A) the percentage of patients in the PHC service diagnosed with these conditions; and (B) the citation frequency of plant use reports to treat these conditions by healers. Healers were also queried about the payment modalities they offer to their patients.</p> <p>Results</p> <p>Plant use reports from healers yielded 1166 responses about 181 medicinal plant species, which are used to treat 67 different health conditions, ranging from general symptoms (e.g. fever and body pain), to more specific ailments, such as arthritis, biliary colic and pneumonia. The results show that treatment offered by traditional medicine overlaps with biomedical health care in the case of respiratory infections, wounds and bruises, fever and biliary colic/cholecystitis. Furthermore, traditional health care appears to be complementary to biomedical health care for chronic illnesses, especially arthritis, and for folk illnesses that are particularly relevant within the local cultural context. Payment from patients to healers included flexible, outcome contingent and non-monetary options.</p> <p>Conclusion</p> <p>Traditional medicine in the study area is adaptive because it corresponds well with local patterns of morbidity, health care needs in relation to chronic illnesses, cultural perceptions of health conditions and socio-economic aspects of health care. The quantitative analysis of plant use reports and patient data represents a novel approach to compare the contribution of traditional and biomedical health care to treatment of particular health conditions.</p

    Predictors of clinical outcomes after periodontal treatment of aggressive periodontitis: 12-month randomized trial

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    Abstract Little is known about the factors that may be used in clinical practice to predict the therapeutic response of aggressive periodontitis patients. The aim of this study was to determine predictors of clinical outcomes after non-surgical treatment of aggressive periodontitis. A total of 24 patients (aged 13-26 years) received oral hygiene instructions, as well as subgingival scaling and root planing. Twelve subjects received systemic azithromycin at random. Clinical variables were assessed at baseline, 3, 6, 9, and 12 months. Baseline microbiological assessment was performed by checkerboard DNA-DNA hybridization. Multivariable models used generalized estimating equations. There were significant improvements in the entire sample in regard to pocket depth, clinical attachment level and bleeding on probing. Significant predictors of a reduction in mean pocket depth were: use of azithromycin, non-molar teeth, generalized disease and baseline pocket depth. Absence of plaque predicted a 0.22 mm higher attachment gain, whereas a baseline pocket depth ≥7 mm predicted a 1.36 mm higher attachment loss. Azithromycin, plaque, and baseline pocket depth were significant predictors of bleeding on probing. The concomitant presence of all three red complex species predicted a 0.78 mm higher attachment loss. It may be concluded that dental plaque, tooth type, disease extent, baseline pocket depth, and use of azithromycin were significant predictors of the clinical response to treatment for aggressive periodontitis in young individuals. Moreover, the presence of multiple periodontal pathogens may predict challenges in achieving a favorable outcome for aggressive periodontitis

    Laserstrahllöten von Leichtmetallen

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